There was once a programmer who was attached to the court of the warlord of Wu. The warlord asked the programmer: ``Which is easier to design: an accounting package or an operating system?''
``An operating system,'' replied the programmer.
The warlord uttered an exclamation of disbelief. ``Surely an accounting package is trivial next to the complexity of an operating system,'' he said.
``Not so,'' said the programmer, ``when designing an accounting package, the programmer operates as a mediator between people having different ideas: how it must operate, how its reports must appear, and how it must conform to the tax laws. By contrast, an operating system is not limited by outside appearances. When designing an operating system, the programmer seeks the simplest harmony between machine and ideas. This is why an operating system is easier to design.''
The warlord of Wu nodded and smiled. ``That is all good and well, but which is easier to debug?''
The programmer made no reply.
A novice programmer was once assigned to code a simple financial package.
The novice worked furiously for many days, but when his master reviewed his program, he discovered that it contained a screen editor, a set of generalized graphics routines, an artificial intelligence interface, but not the slightest mention of anything financial.
When the master asked about this, the novice became indignant. ``Don't be so impatient,'' he said, ``I'll put in the financial stuff eventually.''